George W. Bush pitches in for Jeb as 2016 heats up

Jeb Bush might be his own man, but he showed Thursday he won't hesitate to enlist his brother George, the former president, in his own bid to win the White House in 2016, AFP reports.

George W. Bush wrote a fundraising email in support of his younger brother, who is locked in a tough race for the Republican nomination and is trailing bombastic frontrunner Donald Trump in poll after poll.

"I rarely send emails like this, but I wanted to make sure I asked for your support on behalf of my brother, Jeb," George W. Bush wrote in the first campaign message of its kind by the 43rd president.

"This is a consequential time in our nation's history, and we need a strong leader," he added.

"Jeb took on tough challenges as Florida's governor and delivered results. I know he will do the same as president. "

George W. Bush remains deeply divisive in the United States, where many argue that his Iraq invasion was among the worst foreign policy blunders in US history.

While Jeb has insisted that "I am my own man," he has struggled to emerge from his brother's shadow. He was criticized by presidential rivals recently for enlisting several advisers who worked for George W. Bush.

Trump lashes out

The email hit inboxes as a new Quinnipiac University poll showed Jeb trailing "The Donald," as he is nicknamed, in three key swing states: Ohio, Pennsylvania and Bush's home turf of Florida.

It landed just as Bush began showing backbone against relentless rhetoric by Trump, who on Wednesday hammered Bush for his Iraq and immigration policies and ridiculed his deflated poll numbers.

"He's going down like a rock," Trump told a raucous, overflowing crowd in New Hampshire, which holds the first-in-the-nation primary.

"I don't see how he's electable," Trump taunted, as Bush spoke just miles away at his own New Hampshire town hall.